Christians celebrate this as Pentecost....when the Holy Spirit was given to the church....and this year it is Sunday....May 19. Neither the Jewish Shavuot nor the Christian Pentecost is celebrated on the same secular date every year. So to reiterate....the Christian Pentecost is one day....May 19.....and the Jewish Shavuot is a two day celebration beginning on June 11.
God's Word describes the Feast of Weeks in Deuteronomy 16: 9-12....(there are other references)...."You shall count seven weeks. Begin to count the seven weeks from the time the sickle is first put to the standing grain. Then you shall keep the Feast of Weeks to the LORD your God with the tribute of a freewill offering from your hand, which you shall give as the LORD your God has blessed you. And you shall rejoice before the LORD your God, you and your son and your daughter, your male servant and your female servant, the Levite who is within your towns, the sojourner, the fatherless, and the widow who are among you, at the place that the LORD your GOD will choose, to make his name dwell there. You shall remember that you were a slave in Egypt, and you shall be careful to observe these statutes."
Although the New Testament does not mention that Jesus celebrated the Feast of Weeks....He told his disciples to wait for the....promise of the Father....and they waited....and when the fiftieth day came we read in Acts 2:1-4...."When the day of Pentecost arrived, they were all together in one place. And suddenly there came from heaven a sound like a mighty rushing wind, and it filled the entire house where they were sitting. And divided tongues as of fire appeared to them and rested on each one of them. And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance."
This paragraph in italics from a 2020 post describes why I pay particular attention to these Jewish feasts....
"The dates of the future feasts of Israel are always only a click away for me or anyone who feels that surely major prophetic events will occur on these days. This isn't date setting for we do not know the years....but we do know that God's future plans for the Jewish people will most likely revolve around their feasts. (the horrors of the attack from this past October.....on the last day of Sukkot....is an example)....To prognosticate on this is more than problematic....but to ignore it is being careless to God's warnings to us".